The present invention is directed to a composition of matter which exhibits synergistic activity against contaminating micro-organisms.
Pyrithione, also identified as 2-mercaptopyridine-1-oxide and 1-hydroxypyridine-2-thione and given CAS registry numbers 1121-30-8 and 1121-31-9, and its derivatives are known to be active against a variety of micro-organisms. They, therefore, have been used in a variety of products to inhibit contamination by micro-organisms including cosmetics, lubricants, and water-based paints. The most commonly used derivatives of pyrithione are the alkali metal and heavy metal salts, principally the sodium and zinc salts. See, Nelson and Hyde, "Sodium and Zinc Omadine.RTM. Antimicrobials as Cosmetic Preservatives", Cosmetics & Toiletries, Vol. 96, No. 3, p 87. However, other derivatives such as pyrithione disulfide and the magnesium sulfate adduct thereof have also been proposed as antimicrobial agents. Further details concerning the manufacture and use of pyrithione and its derivatives are found in U.S. Pat. No. 2,745,826 and British Patent Specification No. 761,171, the disclosures of which are hereby incorporated by reference.
Imidazolidinyl urea is the name given to a bacteriocidal compound prepared as described in Example IV of U.S. Pat. No. 3,248,285 (and hereby incorporated by reference) and has been given the CAS registry number 39236-46-9. This compound has been widely used to preserve cosmetics, agricultural products and foodstuffs, paints, lubricants, plastics and textiles from bacteria.
The present invention is predicated upon the discovery that a composition of matter based on the combination of imidazolidinyl urea and pyrithione and/or its derivatives exhibits synergistic activity against the micro-organism C. albicans, a commonly occurring and problematic microbial. The composition, thus, provides a new and effective means for protecting perishable products from the harmful effects of contaminating micro-organisms.